Pathology of Head Injury Flashcards
Commonest cause of traumatic head injury in the UK?
Road traffic accidents and alcohol related incidents including assaults
What are the primary and secondary concerns after trauma to the head?
- Primary: focal/diffuse brain trauma
- Secondary: hypotension, hypoxia, infection, haematoma
How do scores on the glasgow coma scale correlate with severity of head injury?
Score out of 15, 3 the lowest
13-15 - mild injury
9-12 - moderate injury
3-8 - severe injury
What are some significant post trauma complications patients may experience
- Permanent physical disability
- Post traumatic epilepsy
- Intracranial infection
- Psychiatric illness
- Chronic subdural haemorrhage
- Punch drunk dementia
How can a natural disease cause head trauma?
Can cause collapse of the patient that results in head injury
Describe the relationship of the different layers of meninges to the brain and skull
- Dura: adhered to the inner surface of the skull
- Arachnoid: envelopes the brain
- Pia: adhered to surface of the brain, goes into sulci
Why is the scalp quite vulnerable to laceration from blunt force impact?
Because it is attached to the skull making tearing associated with blunt force impact more likely
Types of skull fracture?
- Linear
- Depressed
- Comminuted
- Ring
- Contre-coup
Where do linear skull fractures usually occur?
Usually temporo-parietal from fall/blow to side of head
Becomes “hinge” fracture if continues to skull base
Describe a depressed skull fracture
Common post-trauma complications?
Focal impact pushes skull fragments inwards, damages meninges and blood vessels
Risk of meningitis and post-traumatic epilepsy
Describe a comminuted skull fracture
Fracture resulting in a fragmented skull
Describe a ring skull fracture
Fracture around the foramen magnum
Usually due to fall landing on feet, pushes the skull and spine together
Describe a contre-coup skull fracture
Fracture of the orbital plates caused by a fall onto the back of the head
What are the types of intracranial haemorrhage? Where are they located in relation to the skull/meninges?
- Extradural: between dura and skull
- Subdural: Beneath dura but above arachnoid
- Subarachnoid: subarachnoid space
How does an intracranial haemorrhage result in neurological symptoms/death?
- Increases intracranial pressure (ICP) which compresses the brain causing symptoms
- Too high an ICP can cause pressure on the brainstem which causes herniation of the cerebellar tonsils into the foramen magnum, causing death
What is the most common cause of extradural haemorrhage? Which artery is most often involved with the bleed?
- Skull fracture most common cause (80-90% cases)
- Usually caused by bleeding from middle meningeal artery
Which blood vessels are usually torn in subdural haemorrhage? What can put you at risk of these vessels rupturing?
- Emissary veins
- Atrophic (smaller) brains can cause the veins to get stretched more easily, any rotational/shearing force can make the vessels vulnerable
Which type of haemorrhage can be chronic, particularly in the elderly? Often presents as confusion
- Subdural haemorrhage
What is the “Lucid Interval”? In what types of haemorrhages can it be seen?
- Lucid interval: victim initially seems to be okay, but can catastrophically deteriorate later
- Can occur in extradural and subdural haemorrhage
Most common cause of subarachnoid haemorrhage?
Natural disease - rupture of cerebral artery
What does traumatic basal SAH tell you on a forensic report?
Blow to upper part of side of neck, causing abrupt rotational movement of the head leading to rupture of vertebro-basilar circulation
Causes of intrinsic brain injury?
- Cerebral oedema (can develop in minutes, often malignant, causes raised ICP)
- Cerebral contusion/laceration: direct mechanical damage to brain substance
Other than haemorrhage, what type of CNS damage can trauma do? (badly worded, probably try fix this)
Diffuse traumatic axonal injury
Clinically often results in the patient going into comatose, will probably have concussion and maybe retrograde amnesia after trauma
